History Matching Deltaic Reservoir Models Controlled by Realistic Sedimentological Prior Information

The generation of multiple reservoir models that match production data is one of the advantages of automatic history matching (AMH). Including facies geometry variations within the AHM process without the modeller control, could result in the selection of reservoir models that match production data but lack of sedimentological realism. These unrealistic models will cause problems in production forecasting and reserves estimation. In this work, a technique is proposed to guarantee sedimentological realism within the AHM process.

Building realistic prior models that describe the non-linear dependencies between sedimentological parameters of deltaic systems can prevent the development of geologically unrealistic models. Multi-dimensional priors were generated using One-Class Support Vector Machine. This technique captures hidden relations of deltaic parameters: Delta Plane, Distributary Channel and Mouth bar dimensions. Variables were sampled from the realistic priors in order to assure facies realism. A Multiple Point Statistics (MPS) algorithm is used to model facies in a deltaic reservoir. History-matched models produced under geological realistic constraints reduce uncertainty of the production prediction, ensures the realism of the selected reservoir and also helps in the identification of the reservoir geometry.